4. Selector Lever Set to "N", Cruise Control Does Not Cancel

When the selector lever is moved to "N" range, auto-cruise control is not cancelled.

Park/neutral Position Switch Circuit:

CIRCUIT OPERATION
This circuit transmits the "N" or "P" position signal of the park/neutral position switch to the auto-cruise control-ECU.

When the park/neutral position switch is at the "N" or "P" position, auto-cruise control-ECU terminal number 13 will receives 0 volt.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably an open-circuit in the output signal circuit in "N" range.

TROUBLESHOOTING HINTS
- Malfunction of the park/neutral position switch.
- Damaged harness or connector.
- Malfunction of the auto-cruise control-ECU.

DIAGNOSIS

Required Special Tool:
- MB991223: Harness Set

STEP 1. Check the output circuit voltage at park/neutral position switch connector B-111 by backprobing.
1. Do not disconnect park/neutral position switch connector B-111.
2. Turn the ignition switch to "ON" position.




3. Measure the voltage between terminal 10 and ground by backprobing.
- Voltage should be battery positive voltage. (When select lever is in a position other than "N" range.)
- Voltage should be 0.5 volts or less. (When select lever is in "N" range.)

4. Turn the ignition switch to "LOCK" (OFF) position.

Q: Is the voltage within specifications?

YES: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control-ECU.
Then check that the malfunction is eliminated.
NO: Go to Step 2.




STEP 2. park/neutral position switch connector B-111.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.
NO: Go to Step 3.

STEP 3. Check the circuit at the park/neutral position switch.
1. Disconnect the park/neutral position switch connector B-111.




2. Measure the continuity park/neutral position switch connector terminals.

Q: Is the continuity meet the table above?

YES: Go to Step 4.
NO: Replace the park/neutral position switch.
Refer to Transmission.
Then check that the malfunction is eliminated.

STEP 4. Check the output circuit voltage at auto-cruise control-ECU connector C-21 by backprobing.
1. Do not disconnect auto-cruise control switch connector C-21.
2. Turn the ignition switch to "ON" position.




3. Measure the voltage between terminal 13 and ground by backprobing.
- Voltage should be battery positive voltage. (When select lever is in a position other than "N" range.)
- Voltage should be 0.5 volts or less. (When select lever is in "N" range.)

4. Turn the ignition switch to "LOCK" (OFF) position.

Q: Is the voltage within specifications?

YES: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control-ECU.
Then check that the malfunction is eliminated.
NO: Go to Step 5.




STEP 5. Check auto-cruise control-ECU connector C-21.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.
NO: Go to Step 6.




STEP 6. Check intermediate connector C-25.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.
NO: Go to Step 7.







STEP 7. Check the harness wire between park/neutral position switch connector B-111 and auto-cruise control-ECU connector C-21.

Q: Is any harness wire between park/neutral position switch connector B-111 and auto-cruise control-ECU connector C-21 damaged?

YES: Repair the harness wire and then check that the malfunction is eliminated.
NO: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control- ECU.
Then check that the malfunction is eliminated.